djembe zoom

Advice and questions on keeping your instruments in top form
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By drtom
#38166
Hey Djembefellas (and gals),

I'm rebuilding a djembe that has something on the shell I don't recognize, and maybe you can help identify it.
whiteMystery.jpg
whiteMystery.jpg (698.76 KiB) Viewed 295 times
Once I took the drum apart I found that ? was thicker just below the bearing edge under the rings. I didn't think to take a picture of that before I gave it a cleaning with a wet rag, but here's the shell after the wipe down. I think that the faded area on top is due to the ?
shell.jpg
shell.jpg (555.9 KiB) Viewed 295 times
I had assumed that ? was excess oil that had not been absorbed. I put the shell in the sun so as to wipe off the excess once it had melted, but nothing happened. On closer inspection I perceived that ? was a dry substance that seemed crystaline. I wiped it off with a wet rag and it came off green.

Battery acid? Better ideas please.
User avatar
By djembefeeling
#38169
I saw this a couple of times on djembes, I also think it is mold. David Mühlemann did warn me not to put too much karite or oil on the wood beause excess karite and oil can support mold. And it grows especially just beneath the ring and under the rope, in the shadow, not that much in the parts where the sun can shine to.
User avatar
By drtom
#38170
So mold forms crystals? Mold did cross my mind, but this is new to me.

How do I make sure it doesn't reappear a week after I return it to the owner? (Try to restrain yourself bata d, I need proven solutions. This drum won't be our guinea pig.)
By the kid
#38171
EdIT search for Mineral Efflorescence. Looks like that kind of stuff. Sugar soap stops it and kills it /prevents it.

You could use some orange oil oil or something with some anti bacterial in it like tea tree. Towel the drum too so no residual oil, dust or dirt can stick to wood over time.

You'd really need to explain the drum needs to be well aired and not left in bag or damp area.

Could use the silicca dying sachets in the drum bag too.
Last edited by the kid on Mon Aug 21, 2017 11:42 pm, edited 1 time in total.
User avatar
By djembefeeling
#38172
I am not sure antibacterial stuff is of any use since mold is a fungus, not a bacterium. I am also not sure if the mold is building the crystalin structure or if the rystalin structure is just what is left of the karite.

The drum needs to be stored in a place that has fresh air, no intense humidity and certainly no mold. In my experience you don't have to worry much, though. I just wipe it of with a dry cloth, It usually doesn't come back, and if, less strong than before and you just wipe if of again.
User avatar
By djembefeeling
#38174
o.k. anyway, I use to put as little stuff on the wood as possible. to wipe the film of does the job in my experience. I looked up mineral efflorescence, and though it looks pretty much like it, it seems to be something different. Mineral efflorescence is an issue in masonry, where salt is washed out of stones. that is not a problem in wood, unless it planks the bricks.
User avatar
By drtom
#38176
Thanks kid and df for the useful suggestions. I've done some research and am leaning towards mineral efflorescence. This stuff was clearly crystaline, and when I rubbed it with my hand it was dry and turned to a fine dust. My research did turn up instances of mineral efflorescence on wood, but this was wood on buildings. I don't know how it could end up on a djembe.
User avatar
By djembefeeling
#38181
drtom wrote:I don't know how it could end up on a djembe.
Exactly. That's the million dollar question. I think it couldn't.
User avatar
By batadunbata
#38185
Heh, I'm restraining myself, but we'll see how long that lasts.

I had a drumskin with white powdery crystals on it.
Turned out to be some kind of chemical used to sterilize or preserve the skin. When wet it had a sharp, acrid odor. I'd guess by the smell it was some kind of formaldehyde derivative.
As you know, they have to sterilize skins before import, and I guess that's one way to do it. Ugh.

If that's the case with this drum, which would explain it's location under the rim/rings, it could have gotten onto the shell and under the rim when the drum was headed and the skin was wet, and then dried on. You'd think in that case they'd wipe it off, but maybe they did wipe most of it off, and that's what they couldn't get, since the ropes made difficult to get at?
I'm glad you're restoring it, what a gorgeous drum, beautiful grain and pigment patterns in the wood and so nicely shaped.
Any idea of the wood? I realize it resembles Khadi, but I've seen a bit of heavily figured Djalla too, and with the warm coloring it's hard to tell.
User avatar
By djembefeeling
#38188
batadunbata wrote: some kind of chemical used to sterilize or preserve the skin
Another interesting theory. For some of the drums I have seen with this stuff I can rule it out, because I know the origin of the skins and know they were not preserved in any other way than African sun. They were also not exposed to conditions where mineral efflorescence was an issue.
Last edited by djembefeeling on Fri Aug 25, 2017 6:17 pm, edited 1 time in total.
By the kid
#38189
More info on what it could be. This quote is on 'Bloom' under the wood section. It's an article showing different possible causes for mold like features on materials in an Alaskan museum.

https://alaskawhitestuffid.wordpress.com/
Bloom on wooden artifacts is caused by the application of fats and oils to the surface or from residues left behind from use. There are a number of hypotheses regarding the exact mechanism of the formation of these blooms. Some attribute it to free fatty acids that separate out and crystallize on the surface.(Ordonez and Twilley 1998, 3-4). Analysis by Scott R. Williams (1988, 65-84) found bloom on objects to be primarily composed of a variety of fatty acids including palmitic, stearic, myristic and dicarboxylic acids (such as azelaic). These were present individually or occasionally as mixtures; however palmitic and stearic were the most commonly found (Williams 1988, 68-69). In general, however, it is believed that temperature and humidity levels play important factors in the migration and crystallization process.
User avatar
By djembefeeling
#38194
I think we are closing in on that question. Kid, I go with your "bloom" theory. As David Mühlemann told me, I have to be careful and thrifty with oils and fat on a djembe, because of this white mold stuff. Under the environmental conditions in Conakry with heat plus humidity he learned that the hard way. He uses one drop of oil only for a complete djembe.

On forums of cigar lovers there is an ongoing debate about mold vs. bloom, as I just found out. Since mold does usually not grow on fat, I go with the bloom. There is only one minor doubt, since it is said that "mold leaves a stain when it's removed, but plume comes off without a mark. Plume (or Bloom) is good; essentially this is solidified oil".

The djembe above, on the other hand, seems to have some stains left. That may be different on wood and tabacco leaves.

On cigars, BTW, bloom is a sign for a perfect ripening process. A cigar with bloom has reached the point of perfect to be smoked. So I guess that means that djembe above is ready for smoke, too :giggle:
User avatar
By batadunbata
#38198
The Kid, The lipid efflorescence thing is interesting, but if it's fat or oil, you'd think it wouldn't wipe off with water, it would only harden and become sticky (like how surf wax works to hold the surfer on the wet board).
I think the mineral efflorescence you mentioned is more likely, since there can be mineral desposits in wood, and it would explain why it came out under the rim where the wet skin soaked water into the wood.

But, Djembefeeling, it's possible that what you got was a chemical they used to preserve the skin less toxically, like some kind of salt or mineral. I have nothing to base that on, but if I had fresh wet skins in hot weather I can imagined putting something on them to keep the bacteria from eating them. I don't think goats sweat, so I doubt it's salt from the goat.